Chemours-logoUSA: A potential drop-in replacement for R123 in existing chillers is one of the refrigerants proposed for adding to ASHRAE standards.

The refrigerant, a blend from Chemours, is one of a number proposed for addition to ANSI/ASHRAE Standard 34-2013, Designation and Safety Classification of Refrigerants.

Provisionally assigned the ASHRAE number R514A, the refrigerant is an unusual blend originally developed by Chemours as DR-10 and now known as Opteon XP30. The refrigerant blends the HFO 1336mzz(Z) (74.7%) with trans-1,2-dichloroethene (25.3%), a gas not previously used in refrigerants.

The existing refrigerant R123, although being slightly toxic, is widely used in low pressure centrifugal chillers. However, being ozone depleting, R123 is to be banned in new equipment from January 2020 under the Montreal Protocol.

The HFO R1233zd(E), a non-toxic, non flammable alternative, has already been accepted as a suitable replacement for adoption in new equipment and is offered by Trane in its Series E CenTraVac chiller. Chemours expects R514A to provide a further alternative in new equipment but also as a potential retrofit gas for existing R123 chillers.

Although non flammable, R514A is slightly toxic and proposed for the same B1 ASHRAE safety classification as R123, the refrigerant it is designed to replace. Its toxicity comes from trans-1,2-dichloroethene which is also being put forward for inclusion in its own right as R1130(E) in the safety group B2.

In the blend, the flammability of trans-1,2-dichloroethene is negated by HFO1336mzz(Z), a non toxic, non flammable gas already being manufactured and sold by Chemours as a foam expansion agent.

With a GWP of 7 under AR4, HFO1336mzz(Z) had previously been considered as a single component refrigerant to replace R123 in chiller applications, but although of a similar efficiency, it has a volumetric cooling capacity 21% lower.

The higher proportion of HFO1336mzz(Z) in R514A also dampens the toxicity of trans-1,2-dichloroethene. While R123 has an OEL of 50ppm, the new refrigerant has an improved OEL of 323ppm, falling just short of the class A threshold of 400ppm.

A final decision on the new refrigerant is expected to be made at the June ASHRAE meeting in St Louis.

Chemours low GWP alternative for air conditioners is also proposed for ASHRAE designation and safety classification. Provisionally assigned the ASHRAE number R452B and marketed as Opteon XL55, it has been recommended for an A2L safety classification. Like R32, it is designed as a replacement for R410A.

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